INFLUENCES OF NONSTATIONARY PROCESS ON INTERNAL PARAMETERS AND WIND PROFILES IN THE PLANETARY BOUNDARY LAYER

In this paper,under the assumption of neutral and barotropic atmosphere,by means of the analytic solution of motion equation of PBL,the influences of nonstationary process on the internal parameters u*/A(A is the wind speed at the top of PBL) and φ(the angle between winds near the surface and at the top of PBL) of PBL are investigated in which the wind direction at the top of PBL is a periodic function of time but the wind speed at the top of PBL does not change.The u*/A increases and φ decreases when the wind direction at the top of PBL rotates anticlockwise and vice versa.Hence the parameterization of PBL in the large-scale models derived under the stationary condition should be corrected by accounting for the nonstationary process.The similar results are obtained in the numerical solution of the motion equation of PBL.The influences of this nonstationary process on the profiles of the wind in PBL are also analyzed.